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Im using Acoustic Revive PL, Snotora and Wireworld Starlight. (I prefer them in that order) So far I think the IFI Iusb power makes more difference than the cable. (BTW)
To the skeptics: Jitter and noise are REAL and not imaginary. The digital format still uses analog electrical signals. You can use a scope to see the eye pattern and analyze the signal. I am an EE what are you credentials?
http://www.ifi-audio.com/en/iUSB.html
Right... the switching power supply in a computer has noise. But USB uses 5V DC out (devoting two of the 4 wires to +5 and gnd) and even the link you sent shows the "noise" as 100 (micro)V (100/5,000,000) which can rather easily be evened out by putting a capacitor inline with the voltage if that's important. The spec is for power to be +/- 0.25 V too, so the specification allows for far more variation than the noise cited in your link.
USB signals use negotiated clock rates and half-duplex differential signalling through the twisted pair in a shielded wire. They register as plugged in via a 3.3V draw on a data line and then communicate via signals with voltage differences between both data wires of around 0 volts to 3.3 volts (which is higher voltages than most analog audio signals, where low voltage signals are in danger of EMI-based degredation). The signal is chopped up into so many "chunks" and is registered/rounded to be a 1 or 0. Take a look at the encoding section on wikipedia to see how the wires, which are twisted pair so they'd be subject to the same interference, use the differential signalling and reduce the effects of noise in a packet. http://en.wikipedia.org/wiki/Universal_Serial_Bus#Signaling For USB cables of 1-2 meters, you'd have to get a really cummy cable with obscenely off voltages and noise differing on one wire in the twisted pair vs the other to have that rounding be thrown off ... and you'd have some other major issues if the noise was sufficient to interfere with the signalling rate.
If this were a real issue, then really fast USB connected hard drives would run slower depending on if you were using any old USB cable vs plugged into an expensive "audiophile" usb cable.
Source: years of physics, instrument design course, well along my way to a PhD in Chemistry
For voting purposes, I have a number of USB cables from monoprice as well as other ones from printers and whatnot. I've not heard any difference.
I like monoprice because it's nice to be able to have a cable match the length needed, but have no fear of any USB cable that doens't feel like it's falling apart.
updated list:
Monoprice (6)
Free cable that came with the DAC (4)
Wireworld Starlight (4)
One of the many cables that came with my printer (3)
Audioquest Cinnamon (2)
Cardas Clear (2)
Kimber (2)
Supra USB cable (2)
Acoustic Revive PL (1)
Audioquest Coffee (1)
Audioquest Diamond (1)
Basement printer cables (1)
Furutech GT2 USB cable (1)
Locus Polestar (1)
USB A male to a USB B male adapter (1)
Whiplash Audio Polestar (1)
Wireworld Silver Starlight (1)
(although printer cables are USB A male to B male so the adapter entry, basement printer cables, and cable that came with my printer entries may all refer to the same thing)
